Breakaway post

ABSTRACT

A breakaway post is provided for supporting highway signs or the like. The post is made from independent flat rectangular segments arranged end to end to form three panels, with the segments secured together along their side edges to form a hollow post having a triangular cross section. A plurality of breakaway lines to start the breakup of the post upon impact by an automobile or the like are provided by the ends of the segments. The ends of the segments of any one panel are staggered longitudinally with respect to the ends of the segments of the other panels except at the top and bottom of the post. Staggering of the ends of the segments results in a post having sufficient strength to withstand wind loading even when signs are attached to the post.

United States Patent [72] Inventors [21 Appl. No. [22] Filed [45Patented [73] Assignee [54] BREAKAWAY POST 12 Claims, 12 Drawing Figs.

[52] U.S. Cl 94/l.5 [51] Int. Cl. E04h 12/04 [50] Field ofSearch 52/731,98,

[56] References Cited 3,238,690 3/1966 Wilkins 52/731 3,312,034 4/1967Steinmann... 52/731 746,112 12/1903 Lauridtzen 138/157 775,351 11/1904Hartmann 138/158 3,355,998 12/1967 Roemisch 94/1.5 FOREIGN PATENTS904,693 1954 Germany 52/731 561,800 1957 Italy 40/125 429,807 8/ 1967Switzerland 94/1.5

Primary Examiner-Henry C. Sutherland Att0rney Finnegan, Henderson &Farabow ABSTRACT: A breakaway post is provided for supporting highwaysigns or the like. The post is made from independent flat rectangularsegments arranged end to end to form three panels, with the segmentssecured together along their side edges to form a hollow post having atriangular cross section. A plurality of breakaway lines to start thebreakup of the post upon impact by an automobile or the like areprovided by the ends of the segments. The ends of the segments of anyone panel are staggered longitudinally with respect to the ends of thesegments of the other panels except at the top and bottom of the post.Staggering of the ends of the segments results in a post havingsufficient strength to withstand wind loading even when signs areattached to the post.

Patented March 16, 1971 3,570,376 r 3 Sheets-Sheet l I I v 1 INVENTORSL, 1 :DOLPHIN 0. OVERTONJII I QRUDOLPH B. RUSTIN,JR.

WILLIAM E. HUGHES fineyarz & flza usoa ATTORNEYS Patented March 16, 19713 Sheets-Sheet 2 .3. 914 Van 62 INVENTORS DOLPHIN DOVERTONJII RUDOLPH BRUSTIN,JR. WILLIAM E HUGHES Zkne a z ATTORNEY S Patented S 34 FIG. 10"

3 Sheets-Sheet 5 INVENTORS DOLPHIN D. OVERTON,IN RUDOLPH B. RUSTIN,JR.WILLIAM E. HUGHES ATTORNEYS BEREAKAWAY POST This invention relates toposts, and more particularly to posts which breakaway readily whenstruck by an automobile or the like.

All types of roads, from secondary roads to interstate highways, requiremany signs and other highway markers to inform a driver where he is andwhere and how he should proceed. Also, artificial lighting of the moredensely traveled routes, and many intersections, is desirable. Highwaylights, signs, and markers usually must be elevated on posts above theground for good visibility.

The menace of highway sign and light posts to the safety of a motoristwhose car hits the post has been long recognized. For a number of yearsthe U. S. Bureau of Public Roads has sponsored research designed toprovide highway support structures that are less of an impact hazard fora motorist.

Many factors besides safety go into the design of supports for roadsidesigns or the like. The supports should be (a) strong and stable whensubjected to wind forces, (b) easy to install and maintain, (c) capableof being installed near a roadway to provide for maximum visibility of asign or the like, and (d) designed for an aesthetic appearance.

A common support structure for signs located on interstate highways hasconsisted of vertical wide flange steel beams that are anchored to aconcrete base. This support will support a readable sign, is easilymaintained, and is strong and stable when the sign is subjected to windforces. This type of sign structure, however, may be lethal to theoccupants of a vehicle that happens to hit the support structure.

Among the characteristics of a highway support structure that contributeto the severity of a collision are the mass, the structural rigidity orstiffness, and the resistance to horizontal shearing force of thesupport members. A vehicle which runs into a massive, rigid sign supportmember with great resistance to shearing force may he suddenly stopped,thus causing damage to the vehicle and injury to the occupants.

The need for support structures strong enough to resist wind forces andminor impacts that may be encountered along a highway precludes merelyreducing the size and strength of existing highway support structures toa degree where they are no longer dangerous to the motorist. If thecross-sectional dimensions of existing posts are simply reduced in size,or if the posts are made of weaker materials, the posts may fail underwind load.

Various attempts have been made to reduce the capacity of sign posts toresist shearing forces caused by a vehiclestriking the post withoutreducing the ability of the post to resist overturning moments caused bywind forces on the sign. lt'has been proposed to weaken posts used assupport structures for signs by reducing the shear capacity of the lowerportion of the post, that is, the portion of the post below the level ofvehicle bumpers. If the shear capacity of the post is reduced in thismanner, a severe impact by a vehicle severs the post below bumper leveland the vehicle may continue its forward movement without harmful rapiddeceleration of the vehicle. Posts designed to be sheared by the impactof a vehicle that strikes the posts are called breakaway posts.

Breakaway posts eliminate the problem of stopping too quickly a vehiclethat hits the post but they create another safety hazard. The inertiapossessed by the upper portion of the post after it has been severedfrom the lower portion of the post that is embedded in the ground, maybe dangerous. For example, if a heavy solid wooden post is sheared byimpact from a vehicle that strikes the post, the upper portion of thepost is often sent flying through the air. The flying post is apotentially lethal missile to people in the vicinity of the post andeven to the occupants of the vehicle itself. Tests have shown that thesevered upper portion of breakaway posts often are thrown into a paththat results in a secondary impact with the vehicle.

Breakaway supports have also been made of structural steel members butthese posts possess economic disadvantages because of the amount oflabor they require for fabrication,

assembly, and maintenance. Also, the steel breakaway supports like thewooden breakaway posts present a safety hazard if the upper portion issevered by a vehicle, because the severed upper portion of the supportremains intact and may possess sufficient inertia to injure people inthe'vicinity, and even the occupants ofthe vehicle.

Accordingly, it is a primary object of this invention to provide a newand improved breakaway post which presents a minimal hazard tomotorists.

A further object of the invention is to provide a low cost breakawaypost that is convenient to fabricate and assemble.

A still further object of the invention is to provide a new and improvedbreakaway post that will fail under heavy impacts such as caused by anautomobile, but that possesses sufficient structural strength to supporta highway sign or the like and to resist wind load and other forces towhich such a post is commonly subjected.

Another object of the invention is to provide a lightweight post whichminimizes damage to an object which rams the post.

Still another object of the o invention is to provide a new and improvedbreakaway post that presents a reduced secondary impact hazard to thevehicle and its occupants.

Yet another objectof an embodiment of the invention is to provide a postthat is easily visible clay and night and under adverse weatherconditions.

An additional object of an embodiment of the invention is to provideposts with good resistance to weathering.

Additional objects and advantages of the invention will be set forth inpart in the description whichfollows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and attained bymeans of the instrumentalities and combinations particularly pointed outin the appended claims.

To achieve the foregoing objects and in accordance with the purpose ofthe invention as embodied and broadly described herein, the post of thisinvention comprises at least three panels, each of said panels beingformed of a plurality of independent segments arranged end to end, andmeans for securing the panels together along their edges to form ahollow triangular post, with the ends of the segments of any one panelbeing staggered longitudinally between the top and bottom of the postwith respect to the ends of the segments of the other panels. The endsof the segments provide breakaway lines to start the breakup of thepostupon receiving an impact from a vehicle or the like, while at the sametime the staggering of the ends of the segments permits the post to havesufficient strength at its breakaway lines to withstand wind forces andother light impacts without the post being sheared.

Preferably, the means for securing the panels together along their edgesinclude edge connecting means for securing the edges of the panelstogether and/or wrapping means extending around the outside of each ofthe panels for holding the panels in the form of a triangular post. Theedge connecting means is preferably an adhesive. The wrapping means maycomprise bands spaced longitudinally along the post, or a thin wrap ofmetal or plastic that covers the outer surface of the panels. It ispresently preferred that the plastic wrap comprise a sheet of plasticthat is spirally wrapped over the outside surface of the panels.

Desirably, the post includes means for improving the visibility of thepost. This means may be a part of the wrapping means such as a brightlycolored plastic, or a highly polished metal, or it may be a bright paintdirectly on the post, or a sheet of colored or reflective metal thatcovers at least one panel of the post to increase the visibility of thepost when this panel is positioned perpendicular to the highway.

In a preferred embodiment of the invention, the segments are made ofplywood. It is preferred that the side edges of the segments be miteredto facilitate securing the segments in edge-to-edge relationship to formthe triangular post.

Posts formed according to the invention may also include end securingmeans for releasably attaching together the ends of the adjoiningsegments within each of the panels to add additional strength to thepanels but with the joints being weak enough that they will yield onimpact and thus not destroy the ability of the panels to breakaway atthe ends of the segments.

It is desirable that the new and improved posts of this inventioninclude a top for covering the top edge of the three panels to preventthe entry of moisture in the hollow space between the three panels, andmounting means for permitting a sign to be secured to the post.

The invention may also be described as a support structure comprising aplurality of hollow triangular posts, with each of the posts includingat least three panels, each of the panels being formed of a plurality ofindependent segments arranged end to end, and means for securing thesegments together along their edges to form a hollow triangular postwith the ends of the segments of any one panel being staggeredlongitudinally between the top and bottom of the post with respect tothe ends of the segments of the other panels, the longitudinal axes ofsaid posts aligned in a parallel relationship with at least one panel ofeach post abutting a panel in another post; and means for securing saidposts in a parallel aligned relationship.

Desirably the perimeter of the support structure of this invention isformed by at least one panel from each of the posts in the supportstructure and has the shape of a regular polygon.

The invention consists in the novel parts, constructions, arrangements,combinations, and improvements shown and described. The accompanyingdrawings, which are incorporated in and constitute a part of thisspecification, illustrate embodiments of the invention and, togetherwith the description, serve to explain the principles of the invention.

Of the drawings:

FIG. 1 is a perspective view of a post constructed according to theinvention with a sign mounted thereon;

FIG. 2 is a perspective view of the bottom portion of the post of FIG. 1with a portion ofone panel of the post cut away;

FIG. 3 is a perspective view of the top portion of another embodiment ofa post constructed in accordance with the in vention and including aband-type wrapping means;

FIG. 4 is a perspective view of the top portion of another embodiment ofa post constructed in accordance with the invention and including ametallic-sheet-type wrapping means;

FIG. 5 is a perspective view of the top portion of another embodiment ofa post constructed in accordance with the invention and including aplastic-film-type wrapping means;

FIG. 6 is a sectional view along line 66 of the post of FIG. 1 thatillustrates one embodiment of mounting means for mounting a sign on thepost;

FIG. 7 is a sectional view corresponding to FIG. 6 that illustratesanother embodiment of mounting means;

FIG. 8 is a sectional view corresponding to FIG. 6 that illustrates amodification of the mounting means illustrated in FIG.

FIG. 9 is a perspective view of another embodiment of the postconstructed in accordance with the invention and including a plasticfilm wrapping means;

FIG. 10 is a side elevation of the top portion of a support structureconstructed in accordance with the invention with the securing meansomitted;

FIG. 11 is a top plan view of the support structure of FIG. 10 withsecuring means illustrated; and

FIG. 12 is a horizontal section of another embodiment of the supportstructure of this invention.

As shown in FIG. I, a post generally 10 is provided on which a sign 12may be mounted by mounting means generally 16. Post 10 is shown embeddedin the ground 14.

According to the invention, post 10 is formed by three panels with eachof the panels being made of a plurality of independent segments arrangedend to end. The ends ofthe segments of any one panel are staggeredlongitudinally with respect to the ends of the segments of the otherpanels except at the top and bottom of the post. The ends of thesegments provide breakaway lines to start the breakup of the post uponthe impact of an automobile or the like on the post. However, at thesame time, the staggering of the segments gives the post sufiicientstrength to withstand wind forces and light impacts.

As here embodied, and as best illustrated in FIG. 2, post 10 includesthree panels generally 20, 22, and 24 arranged to form a triangularhollow post.

The triangular shape of the post has been selected since it allowsmaximum rigidity of the assembled post while still maintaining a lowmass.

Each of the panels is made from a plurality of independent segmentsarranged end to end, panel 20 being formed by segments 26, panel 22being formed by segments 28, and panel 24 being formed by segments 30. Aplurality of breakaway lines 32, 34, and 36 are formed at the ends ofsegments 26, 23 and 30, respectively.

Throughout the length of the post the ends of segments 26 of panel 20are staggered longitudinally along the post with respect to the ends ofthe segments 28 and 30 of the other panels. In similar manner, the endsof segments 28 are staggered longitudinally along the post with respectto the ends of segments 26 and 30. However, the ends of the segments aredesirably aligned in the same plane at the top and bottom of the post.As seen in FIG. 2, the bottom end of segments 26a, 28a, and 30aterminate in a plane transverse to the longitudinal axis of the post. I

Each of the segments has a flat rectangular shape and has miteredlongitudinal edges to facilitate the securing of the segments inedge-to-edge relationship to form the triangular post and to providemiter joints that enhance the structural rigidity of the post. It willbe obvious to those skilled in the art that the length of the segmentswithin a panel could vary and that the dimensions of segments making upone panel could vary from the dimensions of segments making up the otherpanels. For example, the length and width of segments 26 could differfrom the length and width of segments 28 and 30. Preferably, however,the dimensions of all the segments are identical so that the segmentsmay be used interchangeably during assembly of the post. It is desirablethat the length of the segments be approximately 6 feet with breakawaylines thus spaced every 2 feet along the post. The presence ofbrcakawaylines at about 2 foot intervals positions a breakaway line betweenground level and the level of the vehicle bumpers when the post isanchored in the ground. Also, breakaway lines 2 feet apart do notexcessively weaken the post.

To align the segment ends at the top and bottom of the post in a commonplane, the length of the segments at the top and bottom ends of the postmay be varied by cutting the segments before or after assembly of thesegments into the post. With reference to FIG. 2, segments 26a and 30aare made shorter than a standard length segment such as segment 30b. Thevariation of the length of segments 26a and 30a allows the bottom end ofthe post 10 to terminate in a plane transverse to the longitudinal axisof the post. The same alignment is achieved at the top of the post in asimilar manner.

The thickness of the segments may be varied to vary the load carryingability of the post. The use of thick segments will result in posts thatmay be used as support structures for even large highway signs.

The segments are made from any strong lightweight material that may beshaped into segments with the side edges of the segments capable ofbeing secured to each other. Plywood is a preferred material ofconstruction for the segments because it is strong, and lightweight, andmay be easily fabricated into segments of the desired size and shape.

As illustrated in FIG. 2, by longitudinally staggering the ends of thesegments of one panel (for example panel 24) with respect to the ends ofthe segments of the other panels (panels 20 and 22) except at the endsof the post, each intermediate segments (that is, each segment not atthe end of the post) contacts the side edges of two segments in each ofthe other two panels. For example, intermediate segment 30b in panel 24contacts the side edges of segments 23a and 28b of panel 22, and theside edges of segments 26a and 26b of panel 20. The longitudinalrelationship of the segments wherein each intermediate segment of apanel contacts two segments in each of the other two panels allowscontinuous assembly of the post as will be later discussed in detail.

In accordance with the invention means are provided for securing thesegments together along their edges. The means for securing the segmentsalong their edges may be edge connecting means for securing the sideedges of the segments of one panel to segments in the other panels, orwrapping means that extend over the outside of all three panels forholding the three panels in the formof a triangular post, or acombination of edge-connecting means and wrapping means. Theedgeconnecting means may comprise conventional fasteners such as nails,staples, screws and the like. Adhesives are a preferred edge-connectingmeans for plywood segments to avoid splitting of the plywood segments.

In the embodiment illustrated in FIGS. 1 and 2, the means for securingthe segments along their edges include edge-connecting means in the formof an adhesive 31 that is applied along the mitered edges of thesegments 26, 28, and 30 and that physically connects the edges of thesegments to each other.

In the embodiments illustrated in FIGS. 35, the means for securing thesegments along their edges include wrapping means extending around theoutside of each of the panels to hold the three panels in the form of atriangular post. The wrapping means preferably weatherproofs the postand improves the visibility of the post.

Referring now specifically to the embodiment illustrated in FIG. 3, thepost is constructed in a similar manner to the embodiment of FIGS. 1 and2 except that wrapping means rather than edge securing means are used tosecure segments 26, 28, and 30 in the triangular relationship. As hereembodied, the wrapping means comprise a plurality of bands 38 that arewrapped around the outside of the panels under tension and secured whilestill under tension by clips 40.

The bands 38 are preferably positioned on the breakaway lines 32, 34,and 36 because this positioning of the bands helps prevent moisture fromreaching the interior of the posts through the openings at the breakawaylines 32, 34, and 36. This positioning of the bands, which arepreferably made of steel, also provides a stable post with goodresistance to overturning moments caused by wind loading.

The means for securing the segments along their edge may include bothbands 38 and edge connecting means such as an adhesive.

The wrapping means of the invention may also comprise a thin metallicsheet that is wrapped about the outside of the panels. In the embodimentillustrated in FIG. 4, a post similar to the post of FIG. I is assembledusing edge connecting means such as glue to secure the segments in theirtriangular relationship. A thin metallic sheet 42 is provided that iswrapped about the outside of all three panels 20, 22, and 24, andsecured by conventional means such as adhesive (not shown). Metallicsheet 42 provides a thin wrap of metal of a thickness that will readilyshear at one or more areas adjacent the breakaway lines in the panelswhen the post is subjected to an impact force such as an automobilehitting the post. The metallic sheet is preferably steel or aluminum andis colored, painted or has reflective material applied thereto toimprove the visibility of the post.

in the presently preferred embodiment of the invention the means forsecuring the segments along their edges includes a wrapping means ofplastic and an edge connecting means of adhesive. The film or coating ofplastic may be reverse printed or color impregnated to improve thevisibility of the post and may be selected to be a material such aspolyvinylfiuoride that protects coloring material on the post fromdeterioration due to the infrared rays of the sun.

The embodiment illustrated in FIG. 5 is similar to the post of FIGS. 1and 2 in that it includes a plurality of segments arranged end to end toform three panels with the ends of the segments of any one panelstaggered longitudinally with respect to the ends of the segments of theother panels. The segments are glued together at their edges. In thepost of FIG. 5, the post is additionally secured by wrapping meanscomprising a plastic coating generally 44 that is applied to the outsideof each of the panels 20, 22, and 24 by spirally wrapping a strip 46 ofplastic film about the panels with successive widths of the strip placedin an overlapping relationship. The strip 46 thus forms convolutions onthe assembled post.

The presently preferred embodiment of the post of this invention,illustrated in FIG. 9, is similar to the post of FIG. 5 except that theplastic coating of FIG. 9 generally 44, that is applied to the outsideof the panels 20, 22, and 24, is formed by overlapping a continuoussheet of plastic film 48. Preferably, the sheet of film has a width thatslightly exceeds the perimeter of the assembled panels so that it may befolded over the panels with the edges of the sheet overlapped and gluedat 4?.

Means for improving the visibility of the post may be secured on theouter surface of the panels. For example, the post may be painted with abright colored paint to improve its visibility and also its weatherresistance, or a thin metal sheet such as aluminum may be positionedover the panels and subsequently covered with a layer of plastic film toimprove the visibility of the post. The plastic film may be printed withstripes or the like to further improve the visibility.

As another means for improving the visibility of the post, the plasticcoating 44 may be dyed easily visible colors or have reflectingmaterial. coated or printed on its inner or reverse surface to increasethe visibility of the post. Also, two plastic strips 46 of contrastingcolors may be used in spirally wrapping the post in alternate spirals togive a barber pole effect to a post.

If desired, the ends of segments 26, 28, and 30 may be releasablyattached to the adjoining ends of the other segments in their respectivepanels, by end-connecting means, for example by butt gluing. Preferably,the end-connecting means are selected so that they release or fail priorto failure of the segments when the post is subjected to a shearingforce. Consequently, releasably attaching the ends of each of thesegments to each adjoining segment facilitates assembly of the postwithout destroying the ability of the panels to breakaway at the ends ofthe segments when subjected to an impact of an automobile or the like.

The wrapping means illustrated in FIGS. 3, 4, and 5 may be designed toincrease the weather resistance of the post by covering the ends of eachsegment of the panel and at least partially sealing the post at thesegment ends against the entry of moisture and foreign elements. Thewrapping means illustrated in FIGS. 4 and 5 form a protective barrierthat extends completely around the exterior of each of the panels.

To prevent the entry of moisture as rain or snow into the hollow centralportion of the post, a cap, generally 50, as shown in FIG. 1, isprovided for covering the top of the post. Cap 50 includes a triangularhorizontal panel 52 and three vertical flanges 54 depending therefrom.The cap may be made of a variety of materials including wood, plastic,or metal.

In accordance with certain embodiments of the invention, the post mayinclude mounting means for permitting a sign or the like to be securedto the post. In the embodiment illustrated in FIG. 6, the mounting meanscomprises a block 56 mounted on panel 26, a hole 57 in panel 20 and awood screw 58. Block 56 may be mounted on panel 20 by conventional meanssuch as nails (not shown). The sign 12 is secured to the post by thescrew 58 that extends through the sign 12, through hole 57 in panel 20,and into block 56.

Another embodiment of the mounting means is illustrated in FIG. '7. Herea bracket 60 is mounted on the outside of the edge seam of panels 22 and24. Panel 20 which is opposite the bracket includes a hole 62 that isaligned with a hole till in bracket 60. The edge seam between panels 22and 24 includes a hole M aligned with both hole 61 in bracket an andhole 62 in panel 20. A bolt 66 is inserted through a sign 12, throughhole 62 in panel 20, through hole 64 along the edge seam, and throughhole 61 in bracket 60. A nut 68 engages the threaded end of bolt 66 tohold it in place.

FIG. 8 illustrates a variation of the mounting means of FIG. 7. Themounting means illustrated in FIG. 8 includes a bracket 70 having athreaded central hole 72 while the hole 61 in bracket 60 of FIG. 7 isnot threaded. Consequently a nut is not necessary to hold the bolt inplace in the embodiment of FIG. 8.

In accordance with the invention, a support structure may be providedthat includes a plurality of the hollow triangular posts having theconstruction described above and means for securing the posts togetherinto a unitary support structure with their longitudinal axes alignedparallel to each other. The support structures of the invention possessdesirable strength and rigidity characteristics in relation to theirmass and may be used as telephone poles or the like.

FIGS. 10 and 11 illustrate a support structure formed by six hollowtriangular members. The individual hollow triangular members of thisembodiment have the structure of the triangular post in illustrated inFIG. 2.

The longitudinal axes of the individual posts are aligned parallel toeach other. The outside edges of two of the panels, panels and 24 ofeach post, abut the outside edge of a panel 24 of one adjacent post andthe panel 20 of another adjacent post, respectively, and the third panel22 of each post forms part of the perimeter of the post.

Preferably, the attached posts from a support structure having theperimeter of a polygon such as the regular hexagon of FIG. 9 with onepanel from each post forming a portion of the perimeter of the supportstructure.

The means for securing individual posts together in the supportstructure may be any conventional means such as adhesives and fasteners(nails or staples), or wrapping means such as the sheet 80 of plastic,film illustrated in FIG. 11, extending around the perimeter of thesupport structure. Preferably the width of sheet 80 slightly exceeds theperimeter of the assembled support structure so that the edges of thesheet overlap at As shown in FIG. 10, the breakaway lines 34 in thepanels making up the outside of the support structure may be staggeredto give the structure a high degree of strength in relation to its mass.When compared to a solid wooden post of comparable strength, supportstructures made from a plurality of triangular hollow posts present areduced impact hazard to a vehicle because of their significantlysmaller mass and because of their tendency to crush and shatter uponimpact.

The posts of the invention may also be used in fence support structures.The reduced impact hazard of such support structures makes themespecially desirable for use in fences located at the boundary of ahighway right-of-way. If a rectangular structure is desired for fencing,the panels may be assembled into a hollow right triangularcross-sectional post such as shown in FIG. 12, and two or more suchright triangular posts may be attached together to form a supportstructure having a rectangular perimeter.

Referring to FIG. 12, the rectangular support structure includes twoidentical hollow triangular posts 90 and 92. Posts 99 and 92 eachinclude panels 94, 96, and 98 with each panel made from a plurality ofsegments with the ends of the segments in one panel staggered inrelation to the ends of the segments of the other two panels asdescribed in the embodiment of FIG. 2.

Panels 94 and 96 form the perimeter of the support structure and theoutside surfaces of these panels form a right angle at their juncture.Panel 98 of post 90 and panel 98 of post 92 are positioned in abuttingrelationship and are held together by an adhesive 100 that is appliedalong the plane of contact of the panels 98 and by a plastic sheet 102that is wrapped around the perimeter of the support structure and gluedat overlap 10 -3.

The assembly of the post of FIGS. 1 and 2 may proceed as follows. Thesegments 26a, 28a, and 30a that make up one end of the post are arrangedto form a hollow triangular member with the interior ends of thesegments 26a, 28a, and 30a being staggered longitudinally with respectto each other. Edge connecting means such as glue is provided to securethe segments together along their adjacent edges.

With reference to FIG. 2, it can be seen that if the bottom of the postis the starting point, portions of segments 26a and 28a extendlongitudinally above segment 300 when attached thereto. Segment 30b isthen attached by glue to the edges of the longitudinally extendingportions of segments 26a and 28a. Subsequently, segment 26b is attachedby glue to portions of segments 28a and 30b. The assembly of the postcontinues with new segments being attached to longitudinally extendingthe portions of segments previously attached together in the triangularhollow configuration.

The assembly of the segments according to the abovedescribed method mayproceed continuously to produce a post of indeterminate length.Individual posts of any desired length may be cut from the assembledsegments.

The post may subsequently be' painted to improve its visibility andweather resistance. Preferably, a top is attached to the upper edges ofthe panels to prevent entry of moisture into the hollow central area ofthe post and mounting means are provided to permit a sign to be securedto the post. The mounting means of FIGS. 7 and 8 may be provided in thefield just prior to installation. Preferably, if the mounting means ofFIG. 6 are utilized, the block 56 is attached to panel 20 prior to orduring the assembly of the segments 26, 28, and 30.

If desired, wrapping means such as illustrated in FIGS. 3-5, may beprovided in place of or in addition to edge connecting means for holdingthe post in a hollow triangular configuration. If an adhesive is used asthe edge connecting means to initially secure the segments in a hollowtriangular configuration, it is preferable that the wrapping means beapplied to the post immediately after application of the adhesive tohelp hold the segments of the post together until the adhesive has set.

The assembly of the post of FIG. 3 may proceed in a manner very similarto the assembly procedure described above for the posts illustrated inFIGS. 1 and 2. The top three segments 262, 282, and 302 at the top ofthe post are arranged in a hollow triangular configuration. Portions ofsegments 262 and 282 extend below segment 301 so the edges of segment30y can be aligned in contact with these portions. Segments 26z, 28z,and 30z are secured together along their edges by wrapping band 38zunder tension about the segments and securing the band with clip 40.Subsequently, the edges of segment 28y are aligned with the protrudingedges of segments 262 and 30y and band 38y is wrapped about thesesegments and secured by clip 40. The assembly of the post continues inthe manner described above by continuously adding segments along thepost and banding the added segment to the adjacent segments that projectfrom the assembled post structure.

In the assembly of the embodiment illustrated in FIG. 5, the plasticstrip is preferably wound around the panels just after the segments havebeen arranged in a triangular hollow configuration and after theapplication of the adhesive. The plastic wrapping material may be woundabout the panels under tension to hold the panels in a triangularconfiguration while the adhesive applied to the edges of the segments issetting. Subsequently, the plastic may be fused to the panels by heatingthe plastic-wrapped panels above the melting point of the plastic.

It will be obvious to those skilled in the art that the plastic coating44 may be applied to posts using other procedures. For example, aplastic envelope conforming generally to the shape of the triangularpost may be placed around the panels of the post, and subsequentlycontracted to securely grip the outside of the post by pulling a vacuuminside the envelope. The plastic may then be fused to the panels by theapplication of heat. Plastic materials which may be used as wrappers forthe posts include a variety of film-forming synthetic organic polymerssuch as polyvinyl chloride, polyethylene, polypropylene, polyethyleneteriphthalate such as Mylar produced by the duPont Co., andpolyvinylfiuoride, such as Tedlar, produced by the duPont Co.

It will be obvious to those skilled in the art that assembly of theposts could proceed by first releasably attaching together the ends ofadjoining segments such as 262 and 26y, and 28z and 28y, and 301 and 30yillustrated in FIG. by, for example, butt gluing to form panels and thensubsequently securing the edges of the panels together. This procedureis particularly advantageous where the post is to be assembled by usingbands, a metallic sheet, or plastic film wrapping means withoutedge-connecting means.

The assembly of the support structures of FIGS. 10 and 11 is initiatedafter completion of the assembly of the individual hollow triangularposts by aligning the six individual posts with the panels and 24 ofeach post abutting the panel 24 on one adjacent post and the panel 20 onanother adjacent post, respectively. If desired the abutting posts maybe glued together. Subsequently, plastic sheet 83 82 is wrapped aroundthe perimeter of the assembled posts and sealed at 82.

The assembly of the support structure of FIG. 12 proceeds in a similarfashion with the additional step of the applying an adhesive to theouter surfaces of one or both of the panels 98 of posts 90 and 92 priorto bringing these posts into abutting contact.

If the intended use of a support structure of the invention requiresthat a protective wrapper and/or means for improving its visibility beprovided, it is desirable to apply the wrapper and/or means forimproving the visibility of the perimeter of the support structure afteralignment of the individual posts in the desired cross-sectionalconfiguration of the support structure.

The term post as used in the specification and claims is intended toencompass primarily members directly anchored in the ground. However,the posts can also be used to perform other functions. For example, thepost may be horizontally disposed between guard rails connected bytension cables to increase the visibility of the guard rails assembly.In this use, the posts would be suspended by insertion of the tensioncables connecting the guard rails through the hollow central opening ofthe posts.

in accordance with the invention new and improved post and supportstructures have been provided which may be fabricated, assembled andmaintained at low cost. The post is designed to provide breakaway linesto start the breakup of the post upon impact from a vehicle or the like.The triangular configuration of the post and the staggering of the endsof the segments making up each panel of the post give the postsufficient strength to withstand wind forces and other light impactswithout breaking away. Further, the post, when struck by a vehicle, doesnot present a serious secondary impact hazard to the vehicle because thepost tends to crush and disintegrates at the first impact and also anylarge portions of the post which remain intact after the first impact,will have a small mass and will have the ability to again break away atthe time of the second impact. The triangular hollow configuration ofthe post makes the post when constructed of plywood, or other suitablematerials, relatively strong and relatively light in weight.

5 The invention in its broader aspects is not limited to the specificdetails shown and described, but departures may be made from suchdetails within the scope of the accompanying claims without departingfrom the principles of the invention and without sad sacrificing itschief advantages.

We claim:

1. In a support structure to be positioned adjacent a highway in alocation where vehicles straying from the roadway could impact thestructure, the improvement comprising a vertically disposed breakawaypost, said breakaway post comprising three flat planar panels, each ofsaid panels being of a uniform cross section throughout its length andformed of a pluralit of independent segments arranged end to end in anend-abut mg rela ionship, each of said segments having a rectangularshape in the plane of the panel it forms, and a trapezoidal crosssection, and consisting of a single sheet of plywood with the end edgesof each segment being planar and extending perpendicularly to the planesformed by the side edges of said segment, adhesive means connecting theside edges of segments in one panel with the side edges of segments inthe other two panels in a mitered abutting relationship, the threepanels forming a hollow triangular post; the end of the segments of anyone panel being staggered longitudinally between the top and bottom ofthe post with respect to the ends of the segments of other panels sothat the ends of said segments provide breakaway lines to start thebreakup of the post upon receiving an impact from a vehicle or the likewhile at the same time the staggering of the ends of said segmentspermits the post to have sufficient strength at its breakaway lines towithstand wind forces and other light impacts without the post beingsheared.

2. The invention of claim 1 including an information-bearing signaffixed on said breakaway post.

3. The invention of claim 1 including a light reflective sheet thatcovers at least one panel of said breakaway post.

4. A support structure comprising: a plurality of triangular members,each of said members including at least three flat planar panels, eachof said panels being formed of a plurality of independent segmentsarranged end to end, and means for securing said segments together alongtheir edges to form a hollow triangular member with the ends of thesegments of any one panel being staggered longitudinally between the topand bottom of the member with respect to the ends of the segments of theother panels, the longitudinal axes of said members aligned in aparallel relationship with at least one panel of each member abutting apanel in another member; and means for securing said members in aparallel aligned relationship.

5. The support structure of claim 4 wherein the perimeter of the supportstructure is formed by at least one panel from each of said members insaid support structure.

6. The support structure of claim 4 wherein the perimeter of the supportstructure is a regular polygon formed by one panel from each of saidmembers.

7. The support structure of claim 5 wherein said support structure has asquare perimeter and is made up of two members the cross section ofwhich are right triangles.

8. The support structure of claim 6 wherein the perimeter of the supportstructure is in the form of a regular hexagon and the support structureis made of six members.

9. The support structure of claim 6 wherein said means to secure saidmembers in parallel aligned relationship is comprised of a film ofplastic wrapped around the perimeter of the support structure.

10. The support structure of claim 7 wherein said means to secure saidmembers in parallel aligned relationship is comprised of a film ofplastic wrapped around the perimeter of the support structure.

11. The support structure of claim 9 wherein the abutting panels of saidmembers are glued together.

12. The support structure of claim 10 wherein the abutting panels ofsaid members are glued together.

1. In a support structure to be positioned adjacent a highway in alocation where vehicles straying from the roadway could impact thestructure, the improvement comprising a vertically disposed breakawaypost, said breakaway post comprising three flat planar panels, each ofsaid panels being of a uniform cross section throughout its length andformed of a plurality of independent segments arranged end to end in anend-abutting relationship, each of said segments having a rectangularshape in the plane of the panel it forms, and a trapezoidal crosssEction, and consisting of a single sheet of plywood with the end edgesof each segment being planar and extending perpendicularly to the planesformed by the side edges of said segment, adhesive means connecting theside edges of segments in one panel with the side edges of segments inthe other two panels in a mitered abutting relationship, the threepanels forming a hollow triangular post; the end of the segments of anyone panel being staggered longitudinally between the top and bottom ofthe post with respect to the ends of the segments of other panels sothat the ends of said segments provide breakaway lines to start thebreakup of the post upon receiving an impact from a vehicle or the likewhile at the same time the staggering of the ends of said segmentspermits the post to have sufficient strength at its breakaway lines towithstand wind forces and other light impacts without the post beingsheared.
 2. The invention of claim 1 including an information-bearingsign affixed on said breakaway post.
 3. The invention of claim 1including a light reflective sheet that covers at least one panel ofsaid breakaway post.
 4. A support structure comprising: a plurality oftriangular members, each of said members including at least three flatplanar panels, each of said panels being formed of a plurality ofindependent segments arranged end to end, and means for securing saidsegments together along their edges to form a hollow triangular memberwith the ends of the segments of any one panel being staggeredlongitudinally between the top and bottom of the member with respect tothe ends of the segments of the other panels, the longitudinal axes ofsaid members aligned in a parallel relationship with at least one panelof each member abutting a panel in another member; and means forsecuring said members in a parallel aligned relationship.
 5. The supportstructure of claim 4 wherein the perimeter of the support structure isformed by at least one panel from each of said members in said supportstructure.
 6. The support structure of claim 4 wherein the perimeter ofthe support structure is a regular polygon formed by one panel from eachof said members.
 7. The support structure of claim 5 wherein saidsupport structure has a square perimeter and is made up of two membersthe cross section of which are right triangles.
 8. The support structureof claim 6 wherein the perimeter of the support structure is in the formof a regular hexagon and the support structure is made of six members.9. The support structure of claim 6 wherein said means to secure saidmembers in parallel aligned relationship is comprised of a film ofplastic wrapped around the perimeter of the support structure.
 10. Thesupport structure of claim 7 wherein said means to secure said membersin parallel aligned relationship is comprised of a film of plasticwrapped around the perimeter of the support structure.
 11. The supportstructure of claim 9 wherein the abutting panels of said members areglued together.
 12. The support structure of claim 10 wherein theabutting panels of said members are glued together.